1. Field of the Invention
The present invention relates to an overhead scanner device, an image acquiring method, and a computer-readable recording medium.
2. Description of the Related Art
When a plurality of documents such as a book having a number of pages are read by a conventional scanner, a user repeats the following operations: opening a target page of the documents, placing the documents on a read platen, and pressing a read start button.
JP-A-2005-167934 discloses a device provided with an area sensor and a line sensor. The device recognizes an area to be read and a size of a document from an image pre-scanned by the area sensor and causes the line sensor to read the document.
Websites of Ishikawa Komuro Laboratory and of Erico Guizzo disclose a technology for correcting a frame of a moving image photographed by a high-speed area sensor to form a scan image (see the website of Ishikawa Komuro Laboratory: “Book Flipping Scanning”, URL: http://www.k2.t.u-tokyo.ac.jp/vision/BookFlipScan/index-j.html, and the website of Erico Guizzo: “Superfast Scanner Lets You Digitize a Book By Rapidly Flipping Pages”, IEEE Spectrum, Mar. 17, 2010, URL: http://spectrum.ieee.org/automaton/robotics/robotics-software/book-flipping-scanning, whose websites were retrieved on May 25, 2010).
However, the conventional scanner has some problem that an operation for causing the scanner to read an image of a document is complicated or that definition of the image is low.
For example, the scanner described in JP-A-2005-167934 has a problem that the operation is complicated because the scanner is a flatbed scanner and it is therefore necessary to repeat the following operations: opening a document pressure plate, turning over a page of the document, placing the document face down, and closing the document pressure plate in order to cause the scanner to read a plurality of documents although a document size, an offset, or the like can be recognized through pre-scanning by the area sensor.
The scanners described in the websites have some problem that expensive equipment has to be used in order to read the document in a high-definition manner although a scan image can be acquired from the moving image by the overhead type high-speed area sensor.